Touch screen panel is an input device, which enable users could input users' instructions by choosing the instructions on panel, such as an image display, by fingers or objects. Users' fingers or objects could directly touch the touch screen panel. The applicable fields are increasing nowadays because this kind of touch screen panel could substitute for a keyboard or mouse of a single input device in connecting to an image display.
A touch unit is integrated into a screen display in In-cell touch screen panel so that the screen panel includes touchable functions. In-cell touch screen panel is a touch control unit manufacture which can be achieved in standards procedure without any problems of lamination or alignment, but further has the advantage of being even lighter, slimmer, frameless, full-flatplane-design-achieving and etc.; moreover, it is a hot point in present research of touch screen panel area.
In in-cell touch screen panel, in-cell touch functions are usually achieved by performing time division multiplex access on the common electrodes. A specific process is as following: an image frame display time period is divided into a display driving time period and a touch drive time period; wherein, all the common electrodes are to be provided with a common electrode voltage of image displaying within the touch drive time period; the common electrodes participating into touch driving are to be provided with the touch driving voltage of touch driving within the touch drive time period, but the common electrodes not participating into touch driving are still to be provided with the common electrode voltage of image displaying within the touch drive time period so that the functions of image displaying and touch driving can be implemented.
An image area corresponding to the common electrodes not participating into touch driving displays well due to the common electrodes are to be provided with the common electrode voltage of image displaying within the touch drive time period, but an image area corresponding to the common electrodes participating into touch driving does not display well due to the touch driving voltage of the common electrodes are higher than the common electrode voltage within the touch drive time period. When consecutive frames are displayed, the common electrodes corresponding to the area are to be provided with the touch driving voltage, which causes a non-uniform image displaying. At the same time, aging rate of liquid crystal molecules of the area corresponding to the common electrodes is increased because the common electrodes are consecutively to be provided with the touch driving voltage.